Hi Ganapatrao,

On Tue, Jun 20, 2017 at 12:37:17PM +0530, Ganapatrao Kulkarni wrote:
> Add code to parse SRAT ITS Affinity sub table as defined in ACPI 6.2
> Later in per device probe, ITS devices are mapped to
> numa node using ITS id to proximity domain mapping.
> 
> Signed-off-by: Ganapatrao Kulkarni <[email protected]>
> ---
>  drivers/irqchip/irq-gic-v3-its.c | 76 
> +++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 75 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/irqchip/irq-gic-v3-its.c 
> b/drivers/irqchip/irq-gic-v3-its.c
> index 45ea1933..5865a75 100644
> --- a/drivers/irqchip/irq-gic-v3-its.c
> +++ b/drivers/irqchip/irq-gic-v3-its.c
> @@ -1833,6 +1833,78 @@ static int __init its_of_probe(struct device_node 
> *node)
>  
>  #define ACPI_GICV3_ITS_MEM_SIZE (SZ_128K)
>  
> +#ifdef CONFIG_ACPI_NUMA
> +struct its_srat_map {
> +     u32                     numa_node;  /* numa node id */
> +     u32                     its_id;  /* GIC ITS ID */
> +     struct list_head        entry;
> +};
> +
> +static LIST_HEAD(its_srat_maps);
> +
> +static int acpi_get_its_numa_node(u32 its_id)
> +{
> +     struct its_srat_map *srat_map;
> +
> +     list_for_each_entry(srat_map, &its_srat_maps, entry) {
> +             if (its_id == srat_map->its_id)
> +                     return srat_map->numa_node;
> +     }
> +     return NUMA_NO_NODE;
> +}

I do not want to come across as pedantic and I understand that the API
to parse static ACPI tables sucks (ie in theory you could avoid stashing
nodes altogether and just use a global variable to parse an ITS ID at
a time but it sucks to go through the SRAT multiple times) but would not
it be easier to just declare an __initdata static array and counter and
be done with this ? We do not need this stuff after boot so I do not see
a point in keeping it in memory and in allocating the nodes dynamically.

Apologies if I was not clear in my comments to the previous set, I did
not like stashing ITS PXM values in arch/arm64 code but I understand you
need an array (__initdata) to avoid reading the SRAT multiple times.

Thanks,
Lorenzo

> +
> +static int __init
> +gic_acpi_parse_srat_its(struct acpi_subtable_header *header,
> +                      const unsigned long end)
> +{
> +     int pxm, node;
> +     struct its_srat_map *srat_map;
> +     struct acpi_srat_its_affinity *its_affinity;
> +
> +     its_affinity = (struct acpi_srat_its_affinity *)header;
> +     if (!its_affinity)
> +             return -EINVAL;
> +
> +     if (its_affinity->header.length <
> +                     sizeof(struct acpi_srat_its_affinity)) {
> +             pr_err("SRAT:ITS: Invalid SRAT header length: %d\n",
> +                     its_affinity->header.length);
> +             return -EINVAL;
> +     }
> +
> +     pxm = its_affinity->proximity_domain;
> +     node = acpi_map_pxm_to_node(pxm);
> +
> +     if (node == NUMA_NO_NODE || node >= MAX_NUMNODES) {
> +             pr_err("SRAT:ITS Invalid numa node %d\n", node);
> +             return -EINVAL;
> +     }
> +
> +     srat_map = kzalloc(sizeof(*srat_map), GFP_KERNEL);
> +     if (!srat_map)
> +             return -ENOMEM;
> +
> +     srat_map->numa_node = node;
> +     srat_map->its_id = its_affinity->its_id;
> +     list_add(&srat_map->entry, &its_srat_maps);
> +     pr_info("ACPI: NUMA: SRAT: ITS: PXM %d -> ITS_ID %d -> NODE %d\n",
> +             srat_map->its_id, pxm, node);
> +
> +     return 0;
> +}
> +
> +static int __init acpi_table_parse_srat_its(void)
> +{
> +     return acpi_table_parse_entries(ACPI_SIG_SRAT,
> +                                     sizeof(struct acpi_table_srat),
> +                                     ACPI_SRAT_TYPE_GIC_ITS_AFFINITY,
> +                                     gic_acpi_parse_srat_its, 0);
> +}
> +#else
> +#define acpi_table_parse_srat_its(void) { }
> +#define acpi_get_its_numa_node(its_id) NUMA_NO_NODE
> +#endif
> +
>  static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header 
> *header,
>                                         const unsigned long end)
>  {
> @@ -1861,7 +1933,8 @@ static int __init gic_acpi_parse_madt_its(struct 
> acpi_subtable_header *header,
>               goto dom_err;
>       }
>  
> -     err = its_probe_one(&res, dom_handle, NUMA_NO_NODE);
> +     err = its_probe_one(&res, dom_handle,
> +                     acpi_get_its_numa_node(its_entry->translation_id));
>       if (!err)
>               return 0;
>  
> @@ -1873,6 +1946,7 @@ static int __init gic_acpi_parse_madt_its(struct 
> acpi_subtable_header *header,
>  
>  static void __init its_acpi_probe(void)
>  {
> +     acpi_table_parse_srat_its();
>       acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_TRANSLATOR,
>                             gic_acpi_parse_madt_its, 0);
>  }
> -- 
> 1.8.1.4
> 

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